..Significantly, the absence of ancestrally amitochondriate eukaryotes (archezoa) among extant eukaryotes is neither evidence for an archaeal host for the ancestor of mitochondria, nor evidence against a eukaryotic host...

..Overall, including ancestral sequences in searches with BLAST and/or HMMER was the most successful approach in the recovery of potential RNase P protein gene homologues, making this a useful technique in early homologue identification...

RNRdb, a curated database of the universal enzyme family ribonucleotide reductase, reveals a high level of misannotation in sequences deposited to Genbank

..Our results indicate evolutionarily stable associations of numerous intronic snoRNAs and miRNAs and their host genes, with probable continued diversification of snoRNA function from an ancestral role in ribosome biogenesis...

..These monopartite TBP-domain proteins suggest that this domain is functional in its own right, and that the TBP domain could have first evolved as an independent protein, which was later recruited in different contexts...

..Any engineer would have replaced cytosine, but evolution is a tinkerer not an engineer. By keeping cytosine and replacing uracil the problem was never eliminated, returning once again with the advent of DNA methylation...